Horizontal gas compressor with free lifting piston

ABSTRACT

A reciprocating gas horizontal compressor with free lifting piston, which includes a piston with straight ends and compression chamber inclined, a crankcase in which are mounted a crankshaft, a connecting rod fixed to a cross head through a bolt which alternately drives into a cross-head body a piston rod in some distance pieces and a cylinder body which contain a cylinder liner, in which is moving rectilinear and alternatively an improved piston, provided with straight ends and compression chamber inclined in areas (m) and (k), with the same angle and in the same plane as the zone (p) from a cylinder head element and respectively in area (n) from a cylinder head element and some magnets fixed to a piston and some magnets fixed in a cylinder and outside and the lower part of a cylinder liner, through which the piston is free lifting on the stroke length with reduced friction.

The invention relates to a horizontal gas compressor equipped with cylinders and free floating pistons used in industrial applications for compressing gas from refinery, petrochemical, chemical industry, storage, compression, methane gas transport or air compression, etc.

State of art: general solutions for horizontal piston compressors manufacturing are known, and in particular those relating to:

patent no. WO 2014139565 A1, belonging to Howden Thomassen Compressors BV, published on Sep. 18, 2014, including the patents mentioned therein, which includes a technical solution for a reciprocating horizontal compressor equipped with free lifting pistons and slides on the gas pillow; patent application A2015 00959, belonging to Compressor Pump Industrial—inventor Prodan Marian, published on Jun. 30, 2017 in BOPI 6/2017 relating to a reciprocating horizontal compressor equipped with inclined heads piston; WO 2014139565 A1 patent disadvantages: the gas used as a gas pillow, who comes from the hot gas from the compression chamber, will run through the piston's nozzle without cooling and will reach the other compression chamber by mixing with cold gas from suction; the suction cold gas will have an increase of suction temperature due to mixing of the cold gas aspirated with hot gas from the gas pillow; hot gas from the gas pillows will provide extra heat in the rider rings area when discharging through the gas pillow nozzle, preventing heat dissipation on the cold gas suction cycle to the suction gas; increasing the temperature at the level of the rider rings made from graphite Teflon or other material, increases the wear rate of rider rings; the gas outlet holes in the lower part of the piston cross the rider rings that can achieve the gas pillow conditions if they are made of a single piece stretched mounted on piston—complicated solution; the suction orifice, with or without valve, and the discharge orifice and/or orifices, with or without valve, on the lower part of the piston made for achievement of the gas pillow, can easily be clogged with the contaminant present in gas, having the effect of no achievement of the gas pillow; the contaminant which is entering in the inside of the piston can only be cleaned by shutting down the compressor and completely removing the piston subassembly; the condition of laminating of the gas with achievement of gas pillow, involves the fulfillment of the reciprocal conditions of the surfaces in contact with micron deviations of the shapes, an impossible condition to be achieved in practice for medium and large process gasses compressors to which the patent refers; for achievement of the gas pillow, the loss of gas from the compressor flow is considerable if there is one orifice provided on each rider ring; where two holes can not meet, in terms of carrying capacity, any piston size due to the small size of gas pillow achieved by the two holes is also mentioned the achievement of the gas pillow option with much more orifices in each rider ring, which will result in even higher debit losses; variation in gas pressure along the length stroke due to compressing phase and increasing of the pressure from the suction pressure to the discharge pressure, will take a pulsation and a variation of gas pressure inside the piston, hence to the discharge pressure of the gas at the bottom of the piston for achievement of the gas pillow , with discontinuity in maintaining the lamination of the gas conditions, with pulsatory achievement of the gas pillow between piston and cylinder liner over the stroke length and with the pulsating dimming of the free lifting effect.

Disadvantages of patent application No. A2015 00959:

does not allow manufacturing of a horizontal compressor with pistons with inclined compression chambers, where to be possible free lifting piston with straight ends in inclined compression chambers.

The problem solved by the invention relates to the manufacture a horizontal gas compressor equipped with double action cylinders and pistons with straight ends and inclined compression chambers, in which the piston is free lifted in the inclined compression chamber with minimal constructive modifications, for a straight head piston in the classic version, applicable to existing compressors or new compressors.

The horizontal gas piston compressor with free lifting piston, according to the invention, eliminates the above disadvantages by using straight-head pistons and inclined compression chambers, one at each end of the piston, together with the inclined head cylinder head fitted to the existing cylinder head and additional equipping of the piston and the cylinder with sectors consist of permanent magnets support for additional guidance of the piston on the length stroke, inside the cylinder, on magnetic pillow to reduce the weight and friction forces, including wear.

The horizontal gases compressor with free lifting piston has the following advantages:

constructive solution of compressor with straight piston head and inclined compression chambers and magnetic pillow, reduce weight, friction and wear, in simplified terms, regardless of the application or the size of the compressor, keeping the straight head shape of the piston; the free lifting of the piston and piston rod in the compressor is not influenced by the gas contaminant under the normal operating conditions; free lifting of the piston and piston rod in the compressor, does not involve additional flow loss from the discharge to the suction; the free lifting of the piston in the compressor is made by direct action of the pressure on the inclined surface of the piston head and by sliding on the magnetic pillow; it is not necessary to pressurize the piston to assure the free lifting of it; the suction gas is not heated by the discharge gas; the free lifting of the piston in the compressor can be designed according to the operating conditions and dimensions of the existing or of a new designed compressor, with the possibility of using together or separately the free lifting piston solutions with the inclined compression chamber and/or magnetic pillow; the full length of the piston, the existing positioning and dimensioning of the rider rings and piston rings are maintained, including the existing restrictions imposed by the relative position of the piston in the cylinder and the valve orifices, without being necessary to change their relative position, while maintaining the availability of making the compression chamber inclined in the piston head; extending the possibility of sliding of the piston in cylinder liner, with low friction, over the entire length of the stroke by introducing the magnetic pillow, with the possibility of simultaneous or separate realization of the free lifting effect, in any of the configurations chosen and depending on the necessities and/or the conditions technical specifications for which conversion is easier to apply;

SHORT DESCRIPTION OF THE DRAWINGS

FIG. 1: Horizontal gases compressor with free lifting piston-section;

FIG. 2: cylinder cross-section of horizontal, gas compressor, with inclined heads and inclined compression chambers, equipped with permanent magnets;

FIG. 3: cross section thru piston and cylinder liner, equipped with permanent magnets;

Is described an example of the invention with reference to FIGS. 1-3, which represent: The horizontal compressor gas piston compressor includes: a crankcase (29) in which a crankshaft (28) is mounted, a connecting rod (27) fixed to a crosshead (26) thru a bolt (25) which alternately drives in a cross-head body (23) a piston rod (7) into some distance pieces (22 and 21) and a cylinder body (8). The separation of the oil from the crankcase is done through an oil wiper case (24) and the gas sealing of the compression chamber is made thru an auxiliary gas packing (20) and a main gas packing (1). Suction and discharge of the compressed gas is made thru some valves (14 and 18) which are fixed in some valve covers (15 and 19). A cylinder compressor (8) which contain a cylindrical liner (6) in which, rectilinear and alternatively moving an improved piston (11) equipped with some guiding bushings (5 and 12) provided with straight ends and inclined compression chambers (k) and (m) with same angle and in the same plane as the area (n) of a cylinder head element(32) mounted on a cylinder head (17) and the zone (p) of a cylinder head element(33) mounted on a cylinder head (2), through which a piston (11) is free lifting on the stroke length. A piston (11) is mounted on a piston rod (8) thru an piston nut (13) and is equipped with some rider rings (10) arranged in some channels of a piston (11) to assure the mounting of a piston (11) and a piston rod (7) without direct contact with a cylinder liner (6) and some piston segments (9) located in some channels of a piston (11) for gas compression and sealing of a piston (11) into a cylinder (8), along the length of the stroke.

In order to have additional free lifting effect and the reduced friction movement, are used some magnets (30) fixed on a piston (11) and some magnets (31) fixed in a cylinder (8) and on the outside diameter and on the lower part of a cylinder liner (6).

Suction of the gas is made thru some of valves (14) along the length stroke of a piston (11) in a cylinder (8) and with compression of the gas on the return stroke of a piston (11), with its free lifting made by the action of the gas pressure in a inclined chamber until the end of the stroke, when some discharge valves (18) are opened; the free lifting action is concurrent and opposed as an event on the double stroke of a piston (11) with present and alternate effect at each compression sequence on the alternate movement of a piston (11), when gas suction is made in the head of a cylinder (8) from the cylinder head (17), concurrent with compressing of the gas between a piston (11) and a cylinder head (2) and a cylinder head element (33) and, respectively, suction of the gas on the return stroke of a piston (11) thru some suction valves (14) and compressing of the gas between a piston (11) and a cylinder head (17) and a cylinder head element (32).

The invention described above is not limited only at the disclosed example, respectively only to horizontal compressors with a single cylinder; the solution can be applied also at the horizontal compressor with many cylinders. 

1. Reciprocating gas horizontal compressor, with free lifting piston, having a piston (11), which includes a crankcase (29), a crankshaft (28) a cross head (26), a distance piece (23), a cylinder (8), a piston rod (7), an oil wiper case (24), an auxiliary gas case (20), a main gas case (1), some suction valves (14) and some discharge valves (18), wherein the piston (11) have some straight ends and some inclined compression chambers (m) and (k) who is making, together with zone (n) from the inclined cylinder head element (32) and zone (p) from an inclined cylinder head element (33), two inclined gas compression chambers in the cylinder (8), one at each end of the cylinder (8) for gas compression and free lifting of the piston (11) with an alternative movement and provided with some permanent magnets (30) fixed to the lower part of the piston (11), on two or more rows and some permanent magnets (31) fixed in the cylinder (8) under the cylinder liner (6), with a magnetic field opposed versus to the field created by permanent magnets (30) that produces simultaneous free lifting and sliding effects, without friction or low friction.
 2. Reciprocating gas horizontal compressor, according to claim 1, wherein a cylinder (8) have at both ends some inclined compression chambers, made from two inclined compression chambers (m) and (k) into a piston (11) and an inclined cylinder head element (32) fixed to a cylinder head (17) and cylinder head element (33) fixed to a cylinder head (2) at the other end, respectively zones (n) and (p).
 3. Reciprocating gas horizontal compressor, according to claim 1, wherein the piston (11) is eqquipped with two guiding bushes (5 and 12) with inclined faces mounted on a piston rod (7), so that together with inclined faces (n) and (p) of some cylinder head elements (32) and (33) belonging to some cylinder heads (17) and respectively (2) are making two gas compression chambers that can realize the free lifting of the piston (11), within the limit of the clearances at the end of the stroke, versus some areas (n) and (p) from the two cylinder head (17) and respectively (2).
 4. Reciprocating gas horizontal compressor, according to claim 1, wherein cylinder (8) have at both ends one cylinder head with inclined areas (n), respective (k), with similar inclined angle with inclined compression chamber (m) and (k) from the piston ends, keeping the clearance at each end of the piston (11) stroke.
 5. Reciprocating gas horizontal compressor, according to claim 2, wherein the piston is eqquipped with two guiding bushes with inclined faces mounted on a piston rod, so that together with inclined faces (n) and (p) of some cylinder head elements and belonging to some cylinder heads and respectively are making two gas compression chambers that can realize the free lifting of the piston, within the limit of the clearances at the end of the stroke, versus some areas (n) and (p) from the two cylinder head and respectively.
 6. Reciprocating gas horizontal compressor, according to claim 2, wherein cylinder have at both ends one cylinder head with inclined areas (n), respective (k), with similar inclined angle with inclined compression chamber (m) and (k) from the piston ends, keeping the clearance at each end of the piston stroke.
 7. Reciprocating gas horizontal compressor, according to claim 3, wherein cylinder have at both ends one cylinder head with inclined areas (n), respective (k), with similar inclined angle with inclined compression chamber (m) and (k) from the piston ends, keeping the clearance at each end of the piston stroke.
 8. Reciprocating gas horizontal compressor, according to claim 5, wherein cylinder have at both ends one cylinder head with inclined areas (n), respective (k), with similar inclined angle with inclined compression chamber (m) and (k) from the piston ends, keeping the clearance at each end of the piston stroke. 